Search Results

You are looking at 1 - 4 of 4 items for

  • Author or Editor: G. Nikolic x
  • All content x
Clear All Modify Search

Summary

Gel-permeation chromatographic (GPC) and visible spectrophotometric methods have been developed and validated for quantitative analysis of complexes of copper(II) with the polysaccharides pullulan and dextran, active pharmaceutical compounds in new antihypocupremical formulations. Linearity, precision, accuracy, specificity, and limits of detection (LOD) and quantification (LOQ) were determined in accordance with ICH Q2(R1) guidelines. GPC was performed isocratically with redistilled water as mobile phase at a flow rate of 1 mL min−1. Visible spectrophotometry was performed in water, using 640 nm for direct assay of the copper(II) complex with pullulan and dextran. The calculated F and t values at the 95% confidence level were less than the theoretical values, showing there were no significant differences between the performance of the methods.

Restricted access
Acta Chromatographica
Authors: N. Ravanić, S. Filipić, K. Nikolić, G. Popović, I. Vovk, B. Simonovska, and D. Agbaba

Summary

A simple and reliable TLC method for analysis of -lipoic acid (LA) with post-chromatographic derivatisation with palladium(II) chloride immersion reagent has been developed and evaluated. Separation of LA was performed on 20 cm × 10 cm RPTLC plates with 2-propanol-methanol-acetone-water-acetic acid 6:4:2:8:0.2 (v/v) as mobile phase. Yellow complexes formed in situ were scanned at 375 nm. The migration distance of LA was 43.0 mm. The relationship between peak area and amount of LA applied was evaluated by use of linear (1.0–3.0 µg per band) and second-degree polynomial (0.5–5.0 µg per band) regression functions. The correlation coefficient (r = 0.999), the limit of quantification (0.39 µg per band), recovery (98.5–105.2%), and precision (1.8–2.9%) obtained by use of the procedure were satisfactory. The method was used for analysis of LA in several drug formulations and selected dietary supplement preparations. The LA content was 99.5–101.0% in the drug formulations, 98.8–99.5% in three of five dietary supplements tested, and 48.0–185.0% in two other dietary supplements.

Restricted access
European Journal of Microbiology and Immunology
Authors: Z. Dakić, A. Nikolić, L. Lavadinović, M. Pelemiš, I. Klun, O. Dulović, B. Milošević, G. Stevanović, I. Ofori-Belić, J. Poluga, Olgica Djurković-Djaković, and M. Pavlović

Abstract

Background

Travel to the tropics is associated with a risk of parasitic infection, which is increasing in parallel with the rise in travel to these areas. We thus examined the prevalence and trend in the occurrence of parasitic infections in Serbian travelers.

Methods

A retrospective analysis of the medical records of all travelers returning from tropical and subtropical areas, who presented at the Institute for Infectious and Tropical Diseases in Belgrade between January 2001 and January 2008, was performed.

Results

Of a total of 2440 travelers, 169 (6.9%) were diagnosed with a parasitic infection, including malaria in 79, intestinal parasites in 84 (pathogenic species in 30 and non-pathogenic in 54), filariasis in four, and visceral leishmaniasis and fascioliasis in one patient each. Importantly, of the whole series only 583 (23.9%) were symptomatic, of which 19.4% were found to be infected with a parasite. The single pathogenic parasite occurring in asymptomatic patients was Giardia intestinalis.

Conclusions

Parasitic infection causing symptomatic disease among travelers returning from tropical areas to Serbia is not infrequent. In view of the expected increase in travel to the tropics, diagnostic protocols for tropical parasitic diseases should take these data into account.

Restricted access
Acta Veterinaria Hungarica
Authors: Sz. Jánosi, Margit Kulcsár, P. Kóródi, L. Kátai, J. Reiczigel, S. J. Dieleman, Judit Anna Nikolic, G. Sályi, Piroska Ribiczey-Szabó, and Gy. Huszenicza

The energy imbalance related predisposition to mastitis was studied in group-fed postpartum dairy cows (n = 333) kept in 4 large-scale units and producing milk of low somatic cell count (SCC). Blood samples were taken on Days 1-3 after calving for assaying some metabolites and hormones related to the negative energy balance (NEB). If mastitis was diagnosed later, aseptic milk samples were taken to identify the pathogens. Considering pathogen types [contagious pathogens: Staphylococcus (S.) aureus, Gram-positive (GP) environmental pathogens, and Gram-negative (GN) environmental pathogens + mastitis with no detectable pathogens (NDP)] separately, stepwise logistic regression was used to analyse the relation between the potential prognostic value of hormones and metabolites and mastitis outbreak. Only the elevated (= 1.00 mmol/l) serum ß-hydroxybutyrate (BHB) levels predisposed the cows to mastitis in the subsequent 4 weeks. This prognostic value of BHB was significant only in GN + NDP mastitis and in cases caused by GP environmental pathogens, but not in S. aureus mastitis (odds ratio: 5.333, 3.600 and 1.333, respectively).

Restricted access